|Date|Winner|Yacht|Loser|Yacht|Score|Delta|
|---|---|---|---|---|---|---|
|September 14, 1983|Liberty|US-40|Australia II|KA-6|1-0|1:10|
|September 15, 1983|Liberty|US-40|Australia II|KA-6|2-0|1:33|
|September 18, 1983|Australia II|KA-6|Liberty|US-40|1-2|3:14|
|September 20, 1983|Liberty|US-40|Australia II|KA-6|3-1|0:43|
|September 21, 1983|Australia II|KA-6|Liberty|US-40|2-3|1:47|
|September 22, 1983|Australia II|KA-6|Liberty|US-40|3-3|3:25|
|September 26, 1983|Australia II|KA-6|Liberty|US-40|4-3|0:41|

Question: what was the score difference for the september 15th game?
Answer: 2